[Effect of local anesthetics on ciliary activity of the human tracheobronchial mucosa (studies in vitro)].

The local cellular toxicity of the local anaesthetics Tetracaine, Propipocain and Lidocaine were investigated in vitro using human tracheal and bronchial epithelium. The ciliary beat of the respiratory epithelium served as an index of the cellular activity. After bronchoscopic explanting the respiratory epithelium was incubated at 37 degrees C in tissue culture medium. The special local anaesthetic drug was added in the selected concentration. The evaluation of ciliary activity was done by light microscope. All local anesthetics tested showed local cytotoxic properties depending on their concentrations. The local toxicity decreased from Tetracaine to Propipocain and Lidocaine. Already 0.1 per cent Tetracaine (20-fold dilution of the clinical concentration) and 0.25 per cent Propipocain (4-resp. 6-fold dilution of the clinical concentration) produced an irreversible stoppage of ciliary activity which may impair the pulmonary clearance. Therefore only Lidocaine is recommended for local anaesthesia of the tracheal and bronchial mucosa because of its low toxicity and its effectiveness.